Haloolefin-based composition

ABSTRACT

The haloolefin-based composition comprising (a) a haloolefin; (b) at least one compound selected from the group consisting of HFO-1234ze, HFC-254eb, HFO-1243zf, HFC-245eb, HFC-245fa, HFC-245cb, HFC-236ea, HFC-236fa, HFO-1225ye, 3,3,3-trifluoropropine, HFC-23, HFC-32, HFC-125, HFC-143a, HFC-134a, FC-1216, HCFO-1233xf, HCFO-1233zd, HCFO-1232xf, HCFO-1223xd, and chloromethane; and (c) water.

TECHNICAL FIELD

The present invention relates to a haloolefin-based composition.

BACKGROUND ART

Hydrofluorocarbons (HFCs), such as HFC-125 and HFC-32, have been widelyused as important substitutes for CFCs, HCFCs, etc., which are known assubstances that deplete the ozone layer. Known examples of suchsubstitutes include “HFC-410A,” which is a mixture of HFC-32 andHFC-125, “HFC-404A,” which is a mixture of HFC-125, HFC-134a, andHFC-143a, etc.

Such substitutes have various applications, such as heat transfer media,refrigerants, foaming agents, solvents, cleaning agents, propellants,and fire extinguishers, and are consumed in large amounts. However,since these substances have a global warning potential (GWP) severalthousand times higher than that of CO₂, many people are concerned thattheir diffusion may affect global warming. As a global warmingcountermeasure, the substances are collected after being used; however,not all of them can be collected, and their diffusion due to leakage,etc., cannot be disregarded. For use in refrigerants, heat transfermedia, etc., although substitution with CO₂ or hydrocarbon-basedsubstances has been studied, CO₂ refrigerants have many difficulties inreducing comprehensive greenhouse gas emissions, including energyconsumption, because of the requirement of large equipment due to thelow efficiency of the CO₂ refrigerants. Hydrocarbon-based substancesalso pose safety problems due to their high flammability.

Hydrofluoroolefins with a low warming potential are recently attractingattention as substances that can solve these problems. Hydrofluoroolefinis a generic name for unsaturated hydrocarbons containing hydrogen,fluorine, and chlorine, and includes substances represented by thefollowing chemical formulae. The description in parentheses followingeach chemical formula indicates the refrigerant number typically usedfor refrigerant purposes.

-   CF₃CF═CF₂ (HFO-1216yc or hexafluoropropene),-   CF₃CF═CHF (HFO-1225ye),-   CF₃CF═CH₂ (HFO-1234yf),-   CF₃CH═CHF (HFO-1234ze),-   CF₃CH═CH₂ (HFO-1243zf)-   CF₃CCl═CH₂ (HCFO-1233xf),-   CF₂ClCCl═CH₂ (HCFO-1232xf),-   CF₃CH═CHCl (HCFO-1233zd),-   CF₃CCl═CHCl (HCFO-1223xd),-   CClF₂CCl═CHCl (HCFO-1222xd),-   CFCl₂CCl═CH₂ (HCFO-1231xf), and-   CH₂ClCCl═CCl₂ (HCO-1230xa).

Of these, fluoropropenes are particularly promising substances ascandidates for refrigerants or heat transfer media with a low GWP;however, they may sometimes gradually decompose over time, etc., andthus are not highly stable. Accordingly, these substances have a problemof gradually reducing performance depending on the situation orenvironment when used in various applications.

To enhance the stability of fluoropropenes, a method for adding a phenolcompound to a composition containing HFO-1234yf and CF₃T is known (see,for example, Patent Literature 1).

CITATION LIST Patent Literature

-   PTL 1: WO2005/103187

SUMMARY OF INVENTION Technical Problem

The above method can improve the stability of HFO-1234yf by the effectof the phenol compound; however, it still has a problem of handlingdifficulty during mixing. The method for improving stability by adding aphenol compound as described above may also reduce the performance offluoropropenes by the effect of the phenol compound, and has a problemin improving stability while maintaining performance.

The present invention was accomplished based on the above, and an objectof the present invention is to provide a highly stable haloolefin-basedcomposition that inhibits decomposition or oxidization.

Solution to Problem

As a result of extensive research to achieve the above object, thepresent inventors found that the above object can be attained bycontaining a very small amount of water in a mixture containing ahaloolefin and other specific substances, and accomplished theinvention. Specifically, the present invention relates to the followinghaloolefin-based compositions.

1. A haloolefin-based composition comprising

-   -   (a) a haloolefin;    -   (b) at least one compound selected from the group consisting of        HFO-1234ze, HFC-254eb, HFO-1243zf, HFC-245eb, HFC-245fa,        HFC-245cb, HFC-236ea, HFC-236fa, HFO-1225ye,        3,3,3-trifluoropropine, HFC-23, HFC-32, HFC-125, HFC-143a,        HFC-134a, FC-1216, HCFO-1233xf, HCFO-1233zd, HCFO-1232xf,        HCFO-1223xd, and chloromethane; and    -   (c) water.        2. The composition according to Item 1, wherein the amount of        the (c) water is 200 mass ppm or less based on the total amount        of the (a) haloolefin.        3. The composition according to Item 1 or 2, which further        comprises (d) oxygen.        4. The composition according to Item 3, wherein the amount of        the (d) oxygen is 0.35 mol % or less based on the total amount        of the (a) haloolefin.        5. The composition according to any one of Items 1 to 4, wherein        the (a) haloolefin is tetrafluoropropene.        6. The composition according to Item 5, wherein the        tetrafluoropropene is 2,3,3,3-tetrafluoropropene.        7. The composition according to Item 5, wherein the        tetrafluoropropene is 1,3,3,3-tetrafluoropropene.        8. The composition according to any one of Items 1 to 7, which        further comprises at least either, or both, of (e)        polyalkyleneglycol and polyolether.        9. A haloolefin-based composition comprising    -   (a) a haloolefin;    -   (c) water; and    -   (e) at least either, or both, of polyalkyleneglycol and        polyolether.        10. The composition according to Item 9, wherein the amount of        the (c) water is 200 mass ppm or less based on the total amount        of the (a) haloolefin.        11. The composition according to Item 9 or 10, wherein the (a)        haloolefin is tetrafluoropropene.        12. The composition according to Item 11, wherein the        tetrafluoropropene is 2,3,3,3-tetrafluoropropene.        13. The composition according to Item 11, wherein the        tetrafluoropropene is 1,3,3,3-tetrafluoropropene.

Advantageous Effects of Invention

According to the haloolefin-based composition of the present invention,the stability of haloolefin in the composition is improved because thecomposition contains water. Specifically, since the double bond in themolecule of the haloolefin can be stably present, and the haloolefindoes not easily cause oxidization, the performance of the haloolefin isnot likely to be lost for a long period of time.

DESCRIPTION OF EMBODIMENTS

Hereinafter, the embodiments of the present invention are explained indetail.

The haloolefin-based composition comprises (a) a haloolefin; (b) atleast one compound selected from the group consisting of HFO-1234ze,HFC-254eb, HFO-1243zf, HFC-245eb, HFC-245fa, HFC-245cb, HFC-236ea,HFC-236fa, HFO-1225ye, 3,3,3-trifluoropropine, HFC-23, HFC-32, HFC-125,HFC-143a, HFC-134a, FC-1216, HCFO-1233xf, HCFO-1233zd, HCFO-1232xf,HCFO-1223xd, and chloromethane, which is produced as a byproduct in theproduction of haloolefin (hereinbelow, simply referred to as “(b)component”); and (c) water.

HFO-1234ze is 1,3,3,3-tetrafluoropropene, HFC-254eb is1,1,1,2-tetrafluoropropane, HFO-1243zf is 3,3,3-trifluoropropene,HFC-245eb is 1,1,1,2,3-pentafluoropropane, HFC-245fa is1,1,1,3,3-pentafluoropropane, HFC-245cb is 1,1,1,2,2-pentafluoropropane,HFC-236ea is 1,1,1,2,3,3-hexafluoropropane, HFC-236fa is1,1,1,3,3,3-hexafluoropropane, HFO-1225ye is1,2,3,3,3-pentafluoropropene, HFC-23 is trifluoromethane, HFC-32 ismethylene difluoride, HFC-125 is 1,1,1,2,2-pentafluoroethane, HFC-143ais 1,1,1-trifluoroethane, HFC-134a is 1,1,1,2-tetrafluoroethane, FC-1216is hexafluoropropene, HCFO-1233xf is 2-chloro-3,3,3-trifluoropropene,HCFO-1233zd is 1-chloro-3,3,3-trifluoropropene, HCFO-1232xf is3,3-difluoropropene, and HCFO-1223xd is1,2-dichloro-3,3,3-trifluoropropene.

The (b) component is a byproduct obtained in the production of the (a)haloolefin. Accordingly, the (b) component is different from the (a)haloolefin.

Because the haloolefin-based composition (hereinbelow, sometimesreferred to as a “composition”) contains water, the double bond in themolecule of the haloolefin can be stably present, and oxidization of thehaloolefin does not easily occur. As a result, the stability of thehaloolefin is improved.

The haloolefin is an unsaturated hydrocarbon having a halogen atom, suchas fluoride or chlorine, as a substituent. In the haloolefin, all of thehydrogen may be substituted with halogen atoms, or part of the hydrogenmay be substituted with halogen atoms. The number of carbon atoms in thehaloolefin is not particularly limited, and it is, for example, 3 to 10.To increase the stability of the haloolefin in the composition, thenumber of carbon atoms in the haloolefin is preferably 3 to 8, andparticularly preferably 3 to 6. The haloolefin contained in thecomposition may be a single compound or a mixture of different two ormore compounds.

Particularly preferable examples of the haloolefin includetetrafluoropropene, pentafluoropropene, and trifluoropropene. The isomertypes of these compounds are not particularly limited. Particularlypreferable examples of the haloolefin include 2,3,3,3-tetrafluoropropene(HFO-1234yf), 1,3,3,3-tetrafluoropropene (HFO-1234ze),1,2,3,3-tetrafluoropropene (HFO-1234ye), 1,1,2,3-tetrafluoropropene(HFO-1234yc), 1,2,3,3,3-pentafluoropropene (HFO-1225ye),1,1,3,3,3-pentafluoropropene (HFO-1225zc), 3,3,3-trifluoropropene(HFO-1243zf), 1,1,1,4,4,4-hexafluoro-2-butene (HFO-1336mzz),1,1,1,2,4,4,5,5,5-nonafluoropentene (HFO-1429myz), etc.

The haloolefin produced by a known method can be used. One such exampleincludes a method for subjecting fluoroalkane to dehydrofluorination inthe presence of a catalyst (a method described, for example, inJP2012-500182A). The number of carbon atoms of the fluoroalkane is notparticularly limited, and it is preferably 3 to 8, and particularlypreferably 3 to 6. For example, when the haloolefin istetrafluoropropene, pentafluoropropane is used as a starting material,and subjected to dehydrofluorination reaction in the presence, of acatalyst to produce tetrafluoropropene. Specifically, when thehaloolefin is 2,3,3,3-tetrafluoropropene (HFO-1234yf),1,1,1,2,3-pentafluoropropane or 1,1,1,2,2-pentafluoropropane is used asa starting material, and subjected to dehydrofluorination reaction inthe presence of a catalyst to produce 2,3,3,3-tetrafluoropropene(HFO-1234yf). When the haloolefin is 1,3,3,3-tetrafluoropropene(HFO-1234ze), 1,1,1,3,3-pentafluoropropane is used as a startingmaterial, and subjected to dehydrofluorination reaction in the presenceof a catalyst to produce 1,3,3,3-tetrafluoropropene (HFO-1234ze). In theabove production method, chromium catalysts, such as chromium oxide orfluorinated chromium oxide, and other metal catalysts can be used ascatalysts, and the reaction can be performed at a temperature in therange of 200 to 500° C.

When 2,3,3,3-tetrafluoropropene is produced according to the aboveproduction method, E- and Z-isomers of 1,3,3,3-tetrafluoropropene(HFO-1234ze), etc. are produced as byproducts. In this case, thebyproducts were typically removed by purifying the resulting product toobtain the target 2,3,3,3-tetrafluoropropene. However, the E- andZ-isomers of 1,3,3,3-tetrafluoropropene produced according to the abovemethod are byproducts and, at the same time, the (b) components in thecomposition. Accordingly, since the (b) component, which is an essentialcomponent in the composition of this embodiment, can also be obtained inthe production of 2,3,3,3-tetrafluoropropene according to the abovemethod, 2,3,3,3-tetrafluoropropene has an advantage in that it can beused in the state containing the byproduct without purification. Ofcourse, in the production of haloolefins other than2,3,3,3-tetrafluoropropene according to the above method as well, aslong as the byproduct is a (b) component, the result can be used withoutpurification as haloolefin in the composition. Accordingly, when thehaloolefin is produced by the method in which fluoroalkane is subjectedto dehydrofluorination in the presence of a catalyst, the byproduct maybe contained in the haloolefin.

The (b) component in the composition is at least one compound selectedfrom the group consisting of HFO-1234ze, HFC-254eb, HFO-1243zf,HFC-245eb, HFC-245fa, HFC-245cb, HFC-236ea, HFC-236fa, HFO-1225ye,3,3,3-trifluoropropine, HFC-23, HFC-32, HFC-125, HFC-143a, HFC-134a,FC-1216, HCFO-1233xf, HCFO-1233zd, HCFO-1232xf, HCFO-1223xd, andchloromethane. These (b) components can be used singly or in acombination of two or more, and the combination is not particularlylimited.

The (b) component that is produced by a known method can be used, and asdescribed above, the component produced as a byproduct in the productionof haloolefin can also be used.

Water is not particularly limited, and purified water, such as distilledwater, ion exchange water, filtered water, tap water, and ultrapurewater obtained by a commercially available device for generating purewater, etc., can be used. However, since water containing acid, such asHCl, may corrode equipment or reduce the haloolefin stabilizing effect,it is preferable to remove HCl, etc., to an undetectable level in atypical analysis method. The amount of acid is preferably 10 mass ppm orless, and more preferably 1 mass ppm or less based on the total amountof the (a) component, (b) component, and (c) component in thecomposition.

Although the pH of the water is not particularly limited, it isgenerally in the range of 6 to 8. When the amount of acid in the wateris in the above range, the pH of the water is generally within the rangeof 6 to 8.

The amount of water in the composition is preferably 200 mass ppm orless based on the total amount of the (a) haloolefin. In this range, thehaloolefin stabilizing effect is fully exhibited. The amount of waterbeing 200 mass ppm or less, and more preferably less than 30 mass ppmbased on the total amount of haloolefin can easily prevent devicecorrosion and the acceleration of haloolefin decomposition. The lowerlimit of the amount of water in the composition is not limited as longas the effect of the present invention is exhibited. For example, it is0.1 mass ppm, and more preferably 3 mass ppm.

When the amount of water is in this range, the stability of haloolefinin the composition is further improved. The amount of water in thecomposition is particularly preferably over 3 mass ppm and less than 30mass ppm. In this range, the stability of haloolefin in the compositionis further improved. The amount of water in the composition being lessthan 30 mass ppm inhibits prevention of refrigerant performance.

The amount of the (b) component in the composition is preferably 0.1mass ppm or more to less than 10,000 mass ppm based on the total amountof haloolefin. In this range, the haloolefin stabilizing effect may notbe significantly inhibited.

The composition may contain other known additives as long as the effectof the present invention is not inhibited. The amount of other additivesis preferably 50 mass % or less, and more preferably 40 mass % or lessbased on the total amount of the composition.

The composition can be prepared by any method. For example, eachcomponent is prepared and mixed in a predetermined composition ratio,thus obtaining a composition.

In the composition, because of the presence of water, the double bond ofhaloolefin is stably present, which is not likely to cause oxidization,attaining highly stable haloolefin. Accordingly, the composition can bestored for a long period of time as compared with typical haloolefins.Moreover, because of the highly stable haloolefin, the performance ofhaloolefin may not be significantly impaired. Accordingly, even when thecomposition is used as a refrigerant or a heat transfer medium, theperformance of the composition as the refrigerant or heat transfermedium is excellent due to the high stability of the haloolefin.

The composition can further contain (d) oxygen. When the compositioncontains (d) oxygen, the amount of the (d) oxygen is preferably 0.35 mol% or less based on the total amount of the (a) haloolefin. When theamount of oxygen is in this range, the stability of haloolefin in thecomposition is further improved. From this point of view, a lower amountof oxygen in the composition is better. However, as described above,since the composition contains water, the stability of the haloolefincan be maintained by the effect of the water, as long as the amount ofoxygen is in the above range. The lower limit of the amount of oxygen inthe composition is, for example, 1 ppm, which is the detection limit ofgas chromatography.

When the composition is used as a refrigerant or a heat transfer mediumas described above, 2,3,3,3-tetrafluoropropene (HFO-1234yf),1,3,3,3-tetrafluoropropene (HFO-1234ze), 1,2,3,3-tetrafluoropropene(HFO-1234ye), 1,2,3,3,3-pentafluoropropene (HFO-1225ye),3,3,3-trifluoropropene (HFO-1243zf), etc., are particularly advantageousas haloolefins.

When the composition is used as a refrigerant or a heat transfer medium,at least either, or both, of (e) polyalkyleneglycol and polyolether canbe contained as a lubricating oil in the composition. When thecomposition contains at least either, or both, of polyalkyleneglycol andpolyolether, the (b) component may be or may not be contained in thecomposition. When the (b) component is not contained in the composition,the composition contains a (a) haloolefin, (c) water, and at leasteither, or both, of (e) polyalkyleneglycol and polyolether. Thestructures of (a) haloolefin and (c) water are the same as above.

The amount of the lubricating oil is 10 to 50 mass % based on the totalamount of components (a), (b) and (c) in the composition; however, it isnot particularly limited to this range because it differs depending onthe specification of the freezer oil tank. When the amount oflubricating oil is in this range, the stability of haloolefin is notimpaired. Moreover, the lubricating oil may further contain polyvinylether (PVE), or may be formed of polyvinyl ether alone.

Examples of polyalkyleneglycol (PAG) include “SUNICE P56,” etc.,produced by Japan Sun Oil Company Ltd. Examples of polyolether (POE)include “Ze-GLES RB32,” etc., produced by JX Nippon Oil & EnergyCorporation.

When the composition contains a lubricating oil, the composition canalso contain (d) oxygen. When the composition contains (d) oxygen, theamount of (d) oxygen is preferably 0.35 mol % or less based on the totalamount of the (a) haloolefin for the same reasons as above.

A refrigerant or heat transfer medium that mainly contains haloolefin islikely to cause decomposition or oxidization when it is in contact withmetal, etc., and is likely to lose performance as a refrigerant or heattransfer medium. However, when the above composition is used as arefrigerant or heat transfer medium, a reduction in the performance ofthe refrigerant or heat transfer medium can be inhibited because of thehigh stability of the haloolefin.

Accordingly, the composition of the present invention can be used invarious applications in addition to refrigerants and heat transfermedia. When the composition is used for purposes other than refrigerantsand heat transfer media, examples of the haloolefin include2,3,3,3-tetrafluoropropene (HFO-1234yf), 1,3,3,3-tetrafluoropropene(HFO-1234ze), 1,2,3,3-tetrafluoropropene (HFO-1234ye),1,1,2,3-tetrafluoropropene (EEO-1234yc), 1,2,3,3,3-pentafluoropropene(HFO-1225ye), 1,1,3,3,3-pentafluoropropene (HFO-1225zc),3,3,3-trifluoropropene (EEO-1243zf), 1,1,1,4,4,4-hexafluoro-2-butene(HFO-1336mzz), 1,1,1,2,4,4,5,5,5-nonafluoropentene (HFO-1429myz), etc.

EXAMPLES

The present invention is explained in detail below with reference to theExamples, but the present invention is not limited to the embodiments ofthe Examples.

Example 1

2,3,3,3-Tetrafluoropropene (hereinbelow simply referred to as“HFO-1234yf”) and water were prepared and mixed to produce three typesof haloolefin-based compositions containing water in amounts of 10 massppm, 200 mass ppm, and 10,000 mass ppm relative to the HFO-1234yf. TheHFO-1234yf was produced, for example, by the method described in Example1 of JP2012-500182A, and JP2009-126803A. HF generated in the aboveproduction was deoxidized by using a water washing column and an alkalicolumn containing an NaOH aqueous solution. The resultinghaloolefin-based composition might contain a byproduct (for example,1,3,3,3-tetrafluoropropene (HFO-1234ze), i.e., component (b)) generatedin the production of HFO-1234yf.

Example 2

1,3,3,3-Tetrafluoropropene (hereinbelow simply referred to as“HFO-1234ze”) and water were prepared and mixed to produce three typesof haloolefin-based compositions containing water in amounts of 10 massppm, 200 mass ppm, and 10,000 mass ppm relative to the HFO-1234ze. TheHFO-1234ze was obtained together with HFO-1234yf by thedehydrofluorination of HFC-245eb according to the method described inJP2012-500182. HF generated in the above production was deoxidized byusing a water washing column and an alkali column containing an NaOHaqueous solution. HFO-1234yf was a (b) component.

Comparative Example 1

A haloolefin-based composition was obtained by the same method as inExample 1 except that water was not added.

Comparative Example 2

A haloolefin-based composition was obtained by the same method as inExample 2 except that water was not added.

Haloolefin Stability Test 1

The haloolefin-based compositions obtained in the Examples andComparative Examples were subjected to a haloolefin stability test asdescribed below. The haloolefin-based composition was added in a mannersuch that the amount of haloolefin was 0.01 mol to a glass tube (ID 8 mmΦ×OD 12 mm Φ×L 300 mm), a side of which was sealed. The tube washermitically sealed. The tube was allowed to stand in a constanttemperature bath in a 150° C. atmosphere, and was kept for one week inthis state. Subsequently, the tube was removed from the constanttemperature bath and cooled, and then acid in the gas inside the tubewas analyzed to evaluate the stability of the haloolefin.

Haloolefin Stability Test 2

The haloolefin-based compositions obtained in the Examples andComparative Examples were subjected to a haloolefin stability test asdescribed below. The haloolefin-based composition was added in a mannersuch that the amount of haloolefin was 0.01 mol to a glass tube (ID 8 mmΦ×OD 12 mm Φ×L 300 mm), a side of which was sealed. Subsequently, oxygenwas enclosed in the tube by adjusting the acid concentration to apredetermined mol concentration (0.010 mol %, 0.115 mol %, or 0.345 mol%) relative to the number of moles of haloolefin filled. The tube wasallowed to stand in a constant temperature bath in a 150° C. atmosphere,and was kept for one week in this state. Subsequently, the tube wasremoved from the constant temperature bath and cooled, and then acid inthe gas inside the tube was analyzed to evaluate the stability of thehaloolefin.

Acid in the gas was analyzed according to the following method. Gasremaining in the tube after cooling was completely coagulated by usingliquid nitrogen. Subsequently, the tube was opened and graduallydefrosted to collect gas in a sampling bag. 5 g of pure water was pouredinto the sampling bag, and acid was extracted into the pure water whileefficiently bringing the pure water into contact with the collected gas.The extract was detected by ion chromatography, and the amounts (massppm) of fluoride ions (F−) and trifluoroacetate ions (CF3COO⁻) weremeasured.

Table 1 shows the test results. In Table 1, “yf” and “ze (E)”respectively indicate “HFO-1234yf” and “HFO-1234ze”. (E) in “ze (E)”indicates the E isomer of HFO-1234ze.

TABLE 1 Example/ Amount of Acid Comparative Amount of oxygen Amount ofwater (mass ppm) No. Example Type of haloolefin (mol %) (mass ppm) F⁻CF₃COO⁻ 1 Comparative yf 0 0 (N.D.) <1 <1 Example 1 2 Example 1 0 10 <1<1 3 Example 1 0 200 <1 <1 4 Example 1 0 10000 <1 <1 5 Comparative 0.0100 (N.D.) 70 550 Example 1 6 Example 1 0.010 10 35 90 7 Example 1 0.010200 10 25 8 Example 1 0.010 10000 <1 10 9 Comparative 0.115 0 (N.D.) 3001850 Example 1 10 Example 1 0.115 10 100 330 11 Example 1 0.115 200 30100 12 Example 1 0.115 10000 3 20 13 Comparative 0.345 0 (N.D.) 10055850 Example 1 14 Example 1 0.345 10 330 1900 15 Example 1 0.345 200 110675 16 Example 1 0.345 10000 50 275 17 Comparative Ze (E) 0 0 (N.D.) <1<1 Example 2 18 Example 2 0 10 <1 <1 19 Example 2 0 200 <1 <1 20 Example2 0 10000 <1 <1 21 Comparative 0.010 0 (N.D.) 80 610 Example 2 22Example 2 0.010 10 30 95 23 Example 2 0.010 200 15 40 24 Example 2 0.01010000 3 20 25 Comparative 0.115 0 (N.D.) 410 1900 Example 2 26 Example 20.115 10 105 385 27 Example 2 0.115 200 50 120 28 Example 2 0.115 1000010 45 29 Comparative 0.345 0 (N.D.) 1100 6020 Example 2 30 Example 20.345 10 335 1930 31 Example 2 0.345 200 130 700 32 Example 2 0.34510000 55 290

The amount of oxygen in each of composition Nos. 5 to 8 in Table 1 wasset to 0.010 mol %. Since composition No. 5 did not contain water, theamount of acid in composition No. 5 was larger than those of compositionNos. 6 to 8 containing water. This indicates that since the amount ofacid in composition No. 5 was larger, the decomposition or oxidizationof HFO-1234yf, which was a haloolefin, advanced as compared tocomposition Nos. 6 to 8. The results indicate that HFO-1234yf, which wasa haloolefin, was stabilized in the compositions containing water. Theamount of oxygen in each of composition Nos. 9 to 12 was 0.115 mol %,and the amount of oxygen in each of composition Nos. 13 to 16 was 0.345mol %; however, the results of composition Nos. 13 to 16 showed asimilar tendency to the results obtained when the amount of oxygen was0.115 mol %. Further, when the haloolefin was HFO-1234ze (Nos. 21 to 24,25 to 28, and 29 to 32), a similar tendency was observed. In compositionNos. 1 to 4 and 17 to 20, the amount of acid was below 1 mass ppm, andit was found that most of the haloolefin decomposition did not proceed.This was presumably because oxygen was not added to the system, causingno oxidization, etc. Accordingly, in the system containing substantiallyno oxygen, the haloolefin was always stable regardless of whether waterwas contained in the composition.

The above clearly indicates that water contained in the compositionstabilizes haloolefin as in the present invention.

1-9. (canceled)
 10. A freezer comprising a haloolefin-based composition,the haloolefin-based composition comprising: (a) HFO-1234yf; (b)HFO-1234ze in an amount of 0.1 ppm by weight or more and 10,000 ppm byweight or less based on the total amount of the (a) HFO-1234yf; (c)water in an amount of 3 ppm by weight or more and 200 ppm by weight orless based on the total amount of the (a) HFO-1234yf; and (d) oxygen inan amount of more than 0 mol % and 0.35 mol % or less based on the totalamount of the (a) HFO-1234yf.
 11. The freezer according to claim 10,wherein the haloolefin-based composition further comprises (e) at leastone component selected from the group consisting of polyalkyleneglycoland polyolester.
 12. A freezer comprising a haloolefin-basedcomposition, the haloolefin-based composition comprising: (a)HFO-1234ze; (b) HFO-1234yf in an amount of 0.1 ppm by weight or more and10,000 ppm by weight or less based on the total amount of the (a)HFO-1234ze; (c) water in an amount of 3 ppm by weight or more and 200ppm by weight or less based on the total amount of the (a) HFO-1234ze;and (d) oxygen in an amount of more than 0 mol % and 0.35 mol % or lessbased on the total amount of the (a) HFO-1234ze.
 13. The freezeraccording to claim 12, wherein the haloolefin-based composition furthercomprises (e) at least one component selected from the group consistingof polyalkyleneglycol and polyolester.